chr17-68537488-A-C

Variant names:

• chr17-68537488-A-C
• rs149451535
• NM_017565.4:c.1615T>G

Variant summary

Our verdict is Likely benign. The variant received -2 ACMG points: 2P and 4B. PM2 BP4_Strong

The NM_017565.4(FAM20A):​c.1615T>G​(p.Leu539Val) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000372 in 1,614,056 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 14/20 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: 𝑓 0.0000066 (0 hom., cov: 32)
  • Exomes 𝑓: 0.0000034 (0 hom.)
• Consequence: FAM20A NM_017565.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: -0.507
• Publications: 0 publications found

Genes affected

FAM20A (HGNC:23015): (FAM20A golgi associated secretory pathway pseudokinase) This locus encodes a protein that is likely secreted and may function in hematopoiesis. A mutation at this locus has been associated with amelogenesis imperfecta and gingival hyperplasia syndrome. Alternatively spliced transcript variants have been identified. [provided by RefSeq, Aug 2011]

PRKAR1A (HGNC:9388): (protein kinase cAMP-dependent type I regulatory subunit alpha) cAMP is a signaling molecule important for a variety of cellular functions. cAMP exerts its effects by activating the cAMP-dependent protein kinase, which transduces the signal through phosphorylation of different target proteins. The inactive kinase holoenzyme is a tetramer composed of two regulatory and two catalytic subunits. cAMP causes the dissociation of the inactive holoenzyme into a dimer of regulatory subunits bound to four cAMP and two free monomeric catalytic subunits. Four different regulatory subunits and three catalytic subunits have been identified in humans. This gene encodes one of the regulatory subunits. This protein was found to be a tissue-specific extinguisher that down-regulates the expression of seven liver genes in hepatoma x fibroblast hybrids. Mutations in this gene cause Carney complex (CNC). This gene can fuse to the RET protooncogene by gene rearrangement and form the thyroid tumor-specific chimeric oncogene known as PTC2. A nonconventional nuclear localization sequence (NLS) has been found for this protein which suggests a role in DNA replication via the protein serving as a nuclear transport protein for the second subunit of the Replication Factor C (RFC40). Several alternatively spliced transcript variants encoding two different isoforms have been observed. [provided by RefSeq, Jan 2013]

PRKAR1A Gene-Disease associations (from GenCC):

• Acrodysostosis 1 with or without hormone resistance

  Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: Ambry Genetics, G2P, Labcorp Genetics (formerly Invitae)
• acrodysostosis with multiple hormone resistance

  Inheritance: AD Classification: DEFINITIVE, SUPPORTIVE Submitted by: Orphanet, Illumina
• Carney complex, type 1

  Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: Ambry Genetics, ClinGen, Labcorp Genetics (formerly Invitae), G2P
• pigmented nodular adrenocortical disease, primary, 1

  Inheritance: AD Classification: STRONG, MODERATE Submitted by: Genomics England PanelApp, Ambry Genetics
• acrodysostosis

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• Carney complex

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• familial atrial myxoma

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• primary pigmented nodular adrenocortical disease

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Likely_benign. The variant received -2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.040578634).

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_017565.4. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	FAM20A	NM_017565.4	MANE Select	c.1615T>G	p.Leu539Val	missense	Exon 11 of 11	NP_060035.2	Q96MK3
	FAM20A	NM_001243746.2		c.1201T>G	p.Leu401Val	missense	Exon 12 of 12	NP_001230675.1
	PRKAR1A	NM_001276290.1		c.973+7487A>C		intron	N/A	NP_001263219.1	P10644-2

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	FAM20A	ENST00000592554.2	TSL:1 MANE Select	c.1615T>G	p.Leu539Val	missense	Exon 11 of 11	ENSP00000468308.1	Q96MK3
	FAM20A	ENST00000226094.9	TSL:1	n.1293T>G		non_coding_transcript_exon	Exon 11 of 11
	FAM20A	ENST00000882126.1		c.1645T>G	p.Leu549Val	missense	Exon 12 of 12	ENSP00000552185.1

Frequencies

GnomAD3 genomes AF: 0.00000657 AC: 1 AN: 152156 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.000207

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.00

Gnomad OTH AF: 0.00

GnomAD2 exomes AF: 0.0000159 AC: 4 AN: 251078 AF XY: 0.0000147

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.0000289

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.000326

GnomAD4 exome AF: 0.00000342 AC: 5 AN: 1461782 Hom.: 0 Cov.: 30 AF XY: 0.00000413 AC XY: 3 AN XY: 727166

African (AFR) AF: 0.00 AC: 0 AN: 33476

American (AMR) AF: 0.0000224 AC: 1 AN: 44712

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26128

East Asian (EAS) AF: 0.00 AC: 0 AN: 39698

South Asian (SAS) AF: 0.00 AC: 0 AN: 86200

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53416

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5768

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1111988

Other (OTH) AF: 0.0000662 AC: 4 AN: 60396

GnomAD4 genome AF: 0.00000657 AC: 1 AN: 152274 Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0 AN XY: 74464

⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5.

African (AFR) AF: 0.00 AC: 0 AN: 41550

American (AMR) AF: 0.00 AC: 0 AN: 15300

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3472

East Asian (EAS) AF: 0.00 AC: 0 AN: 5172

South Asian (SAS) AF: 0.000208 AC: 1 AN: 4818

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10618

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 294

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 68024

Other (OTH) AF: 0.00 AC: 0 AN: 2114

⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5. (p-value = 0), which strongly suggests a high chance of mosaicism in these individuals.

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.00000378

ExAC AF: 0.00000824 AC: 1

ClinVar

ClinVar submissions as Germline

Significance: Uncertain significance

Revision: criteria provided, single submitter

Pathogenic	VUS	Benign	Condition
-	1	-	Inborn genetic diseases (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.060
BayesDel_addAF	Benign	-0.22	T
BayesDel_noAF	Benign	-0.46
CADD	Benign	3.7
DANN	Benign	0.97
DEOGEN2	Benign	0.0069	T
Eigen	Benign	-1.1
Eigen_PC	Benign	-1.3
FATHMM_MKL	Benign	0.039	N
LIST_S2	Benign	0.70	T
M_CAP	Benign	0.029	D
MetaRNN	Benign	0.041	T
MetaSVM	Benign	-0.93	T
MutationAssessor	Uncertain	2.1	M
PhyloP100		-0.51
PrimateAI	Benign	0.26	T
Sift4G	Uncertain	0.043	D
Polyphen		0.0020	B
Vest4		0.033
MutPred		0.089		Gain of glycosylation at T540 (P = 0.0909)
MVP		0.27
MPC		0.16
ClinPred		0.031	T
GERP RS		-7.8
Varity_R		0.051
gMVP		0.23
Mutation Taster		=98/2	polymorphism

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.0		Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Other links and lift over

dbSNP: rs149451535; hg19: chr17-66533629;